Alternate Load Device (Ald); Changing Exercise Timers; Shutting Down The Unit; Emergency Stop Switch - Generac Power Systems MDG25IF4 Owner's Manual

Operation
A
F
E
Figure 3-9. Transfer Switch Operation
A
Incoming utility power
Emergency distribution panel (generator
B
power)
C Main distribution panel (utility power)
D Transfer switch
E
Power from generator
F
Utility meter
WHITE
Incoming utility power
GRAY
Normal utility power circuit
BLACK
Emergency generator power circuit

Alternate Load Device (ALD)

The ALD system mitigates wet-stack and low-load
conditions by increasing engine load. It monitors
generator load, activating when power capacity is under-
utilized, and deactivating when generator is appropriately
loaded—or as needed, to maintain appropriate engine
temperature.
The ALD device is a fluid (coolant) shearing device,
routing some coolant from the engine to the cylinder
head. The device is belt driven, powered by the
crankshaft pulley.
See Maintenance for maintenance requirements.

Changing Exercise Timers

If exercise timers or scheduled runs are needed, contact
a GMASD for assistance.

Shutting Down the Unit

Prior to shutting down the unit, check with personnel
using power supplied by the generator and let them know
the power is going to be turned off. Verify the power shut
32
down will not create any hazards by accidentally turning
off equipment that needs to be kept on (pumps,
compressors, lights, etc.).
B
1. Remove all loads from the generator by opening all
C
2. Allow engine to run for approximately five minutes
3. Press the red engine STOP (O) button on the
D
002807
4. After the unit shuts down, wait two minutes after
NOTE: Turning off the control panel before the controller
finishes updating could cause a loss of data.
NOTE: For extended storage time, disconnect the
battery. See the engine operator's manual for extended
storage requirements.

Emergency Stop Switch

Equipment Damage. The emergency stop switch is
not to be used to power down the unit under normal
operating circumstances. Doing so could result in
equipment damage.
See
emergency stop switch. The red button is clearly labeled
EMERGENCY STOP. The switch can be accessed and
activated with all doors closed and locked.
Activate the emergency stop switch by pushing the
button in until it locks down. This trips the main circuit
breaker which then opens the contact, disconnecting the
load to the connection lugs. This will also open the fuel
circuit, shutting down the engine. The emergency stop
fault will be displayed on the control panel. The switch
will remain closed until it is pulled out.
circuit breakers (turn OFF (O)).
to allow it to cool down.
controller. This will result in the generator going
into the shutdown cycle. If the unit does not shut
down within 15 seconds, a stop fail alarm will be
displayed on the display screen.
engine shutdown for controller actuated actions to
complete and then set the control power switch to
OFF (O).
CAUTION
Figure 3-10. The unit is equipped with one
Figure 3-10. Emergency Stop Switch
Owner's Manual for Mobile Generator
(000246b)
011198